Our new hearing protection calculation tool for client use

Our new hearing protection calculation tool for client use

How do you know if the hearing protection device (HPD) your workers are wearing allows suitable protection against the noise they are exposed to?

There are various methods for estimating the performance of hearing protection, such as SNR or HML. But the octave band analysis method is regarded as the gold standard.

This method takes the frequency bands of your noise levels and applies this against the attenuation data from the HPD manufacturer to determine if that type of HP is suitable against that specific noise source.

Our occupational noise exposure assessments involve taking noise measurements in the workplace, including the noise levels in frequency bands. With this data we estimate the ‘protected’ level under the HP using the manufacturer’s octave-band mean attenuation and standard deviation data.

Sounds complicated. But we’ve made it simple for you with an auto-populated calculator!

Our inspiration comes from the HSE’s HPD calculator. The HSE provide a spreadsheet to calculate the HPD’s performance (hearingcalc.xlsm (live.com)). This requires the user to input the mean attenuation and standard deviation data from the HPD manufacturer manually. As well as the frequency bands per noise location.

This is an excellent spreadsheet and of much use to employers. But we have taken the grunt work out and created a quick and easy-to-use version with hundreds of HPD attenuation data already entered. We supply you with your noise data during our on-site assessment, which then feeds into our HPD attenuation calculation spreadsheet. An example of the noise data we would gather on site is shown here-

We would select the HPD you already have in place (if so) to show if this is suitable against that noise source. In this example we see that the HPD in use is causing over-attenuation. And so alternative hearing protection with a lower attenuation rating is recommended.

Our HP attenuation calculation spreadsheet can make this task easy by selecting the drop-down window under ‘HPD supplied’ and selecting an alternative HPD. This would then automatically update the ‘Level at Ear with HPD Attenuation dB(A)’ column and show if this alternative HPD selected allowed for a noise reduction at ear within the desired range of 70-79dB(A). (We allow a +4dB correction for “real world” conditions within this calculation, which is standard practice).

We must emphasis however that the octave band analysis will give an estimated ‘’in-ear’’ noise level. But that HPD performance also depends on a suitable fit to the wearer and whether the wearer has been given sufficient information, instruction and training around the risks of exposure to noise and the correct use of the hearing protection. Therefore focus must also be given on HPD fit training, ensuring a suitable fit to that wearer, maintenance of this control measure and providing suitable storage conditions.

Contact us for more information.